The proposed project seeks to understand the neurobiology of behavioral inhibition and disinhibition in children using the neuroimaging method of functional MRI. Over a decade of research has established behavioral and physiological profiles of inhibited and uninhibited children. Extreme fear and avoidance of novelty and a more reactive physiological profiles of inhibited and uninhibited children. Extreme fear and avoidance of novelty and a more reactive physiological profile (e.g., higher heart rate, higher salivary cortisol levels, and greater relative right frontal EEG asymmetry) characterize behaviorally inhibited children. This behavioral and physiological profile puts these inhibited children at risk for the development of anxiety disorders; therefore, investigation of the neurobiology could provide important insight into these behavioral profiles. Despite the extensive examination of these types of children, there are no published studies to date that have utilized neuroimaging techniques. The general aim of this proposal is to begin to understand the neural circuitry characteristic of these two types of children. The project will involve identification of a sample of inhibited and uninhibited 7-9 year-old child and a functional MRI follow-up of these children at ages 8- 1q0 years. Using two experiments, both involving emotional contents, we hypothesize that the two groups will differ primarily in activity of the amygdala and PFC.